This invention relates to filters which are top mounted and suspended from a mounting floor which has a plurality of apertures for receiving such filters. Such filters normally carry a "top removal plate," which is a term of art for a plate member which is connected to the top of the filter and extends beyond the outer confines of the filter, and is used to mount the filter to the mounting floor.
A conventional cylindrical-type top mounting filter generally has a top end plate which carries the top removal plate. The end plate is generally ring-shaped, having an inner edge corresponding with the inner diameter of the ring and an outer edge corresponding with the outer diameter of the ring. Generally, both the inner and the outer edges of the end plate are flanged or bent downwardly toward the filter medium thereby creating an inverted channel in which the filter medium rests. The filter medium is supported within the channel of the end plate by means of an adhesive which is used to adhere the edges of the filter medium to the end plate. Thus, the inner flanged edges of the end plate correspond with and form a part of the bore of the filter through which the cleaned air exits.
The top removal plate on a conventional top removal filter is also ring-shaped and has a central bore which is substantially the same diameter as the channel of the filter. The top removal plate is merely spot welded on the top surface of the end plate, and thus, there is a seam which runs between the end plate and the top removal plate where leakage of dust particles and other impurities may occur. When using conventional filters of this type, a common procedure is to run a bead of caulking around the inner or outer edge of the end plate where the seam exists between the top face of the end plate and the top removal plate to prevent the dust particles from leaking therebetween.
However, this procedure is both inefficient and costly. There is a long-felt need for a filter where the leakage path between the top removal plate and the end plate can be effectively eliminated without performing the extra time-consuming and costly procedure of caulking the seam around the perimeter of the end plate where the end plate meets the surface of the top removal plate.
The construction of the invention described in the present application eliminates the need for caulking the seam around the perimeter of the end plate, and is thereby a clear improvement over the conventional prior art.